xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/subvti3.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-- subvti3.c - Implement __subvti3 -----------------------------------===//
2*0b57cec5SDimitry Andric //
3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*0b57cec5SDimitry Andric //
7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
8*0b57cec5SDimitry Andric //
9*0b57cec5SDimitry Andric // This file implements __subvti3 for the compiler_rt library.
10*0b57cec5SDimitry Andric //
11*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
12*0b57cec5SDimitry Andric 
13*0b57cec5SDimitry Andric #include "int_lib.h"
14*0b57cec5SDimitry Andric 
15*0b57cec5SDimitry Andric #ifdef CRT_HAS_128BIT
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric // Returns: a - b
18*0b57cec5SDimitry Andric 
19*0b57cec5SDimitry Andric // Effects: aborts if a - b overflows
20*0b57cec5SDimitry Andric 
__subvti3(ti_int a,ti_int b)21*0b57cec5SDimitry Andric COMPILER_RT_ABI ti_int __subvti3(ti_int a, ti_int b) {
22*0b57cec5SDimitry Andric   ti_int s = (tu_int)a - (tu_int)b;
23*0b57cec5SDimitry Andric   if (b >= 0) {
24*0b57cec5SDimitry Andric     if (s > a)
25*0b57cec5SDimitry Andric       compilerrt_abort();
26*0b57cec5SDimitry Andric   } else {
27*0b57cec5SDimitry Andric     if (s <= a)
28*0b57cec5SDimitry Andric       compilerrt_abort();
29*0b57cec5SDimitry Andric   }
30*0b57cec5SDimitry Andric   return s;
31*0b57cec5SDimitry Andric }
32*0b57cec5SDimitry Andric 
33*0b57cec5SDimitry Andric #endif // CRT_HAS_128BIT
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